Rhodamine-based chemosensors: progress in ion detection, molecular logic, and bioimaging with future perspectives on CPL-active and photolithography-driven systems

Rhodamine-based chemosensors have garnered significant attention due to their remarkable photophysical properties, high sensitivity, and versatility in structural modification. This review highlights recent developments in rhodamine-derived fluorescent probes, with a focus on their coordination-driven ion recognition mechanisms, integration into molecular logic gate systems, and applications in biological imaging. We first discuss the underlying principles of rhodamine spirolactam ring-opening mechanisms, emphasizing their selective response to various s-, p-, and d-block element metal ions. The coordination chemistry involved in these recognition processes is critically examined, revealing structure–activity relationships and trends in selectivity and sensitivity. Subsequently, we explore how these ion-responsive systems have been engineered into molecular logic gates capable of performing Boolean operations at the molecular level, offering promising prospects for information processing and intelligent diagnostics. We summarize recent progress in applying rhodamine-based chemosensory for live cell and in vivo imaging, evaluating their biocompatibility, fluorescence response, and target specificity. Finally, future directions are proposed for the rational design of next-generation rhodamine-based chemosensors with enhanced performance in complex environments, offering promising prospects for chemical sensing, molecular computing, and biomedical imaging.